Mark-Up Percentage

[sukhman]

A trader marks his goods at a certain percentage over his cost price and then gives a 30 % discount , thereby making 5% profit . What is mark up percentage ?
a) 60 b)65 c)55 d) 50 E)45

[GMATGuruNY]

A trader marks his goods at a certain percentage over his cost price and then gives a 30 % discount , thereby making 5% profit . What is mark up percentage ?
a) 60 b)65 c)55 d) 50 E)45

Let the cost price = 100.
We can PLUG IN THE ANSWERS, which represent the mark-up.
When the regular selling price is discounted by 30%, the result will be a discounted selling price of $105 -- the price required to yield a profit of 5%.

D: 50%
Regular selling price = 100 + (50% of 100) = 100+50 = 150.
Price with a 30% discount = 150 - (30% of 150) = 150-45 = 105.
Success!

The correct answer is D.